Pontic tooth



March 16, 1948. .LB; EARMAN PONTIC TOOTH Filed June 29, 1945 EAR/WANPatented Mar. 16, 1948 UNITED STATES PATENT v OFFICE 3 Claims.

This invention relates to a construction of a pontic designed to replacea natural tooth, and more especially to an assembly of this type inwhich the artificial tooth is provided with a pin by which it isattached to a metallic backing forming a part of the bridgework.

One of the objects of the present invention is to provide a ponticof thetype described in which the pin is fused to the center of the tooth andprotrudes at an angle to the center axis of the tooth.

Another object of the present invention is to provide a pontic of thetype described in which the pin extends lingually at an angle to thetooth and fits a tube which is attached to a metallic backing.

A further object of the present invention is to provide a ponticstructure of the type described in which all of the parts areinterchangeable and in which the artificial tooth may be easily attachedto the metallic backing and replaced if it becomes necessary.

With these and other objects in view which may be instant to myimprovements, the invention consists in the procedural steps and theparts and combinations hereinafter set forth and claimed with theunderstanding that the necessary elements comprising the invention andthe procedural steps of its construction may be varied by those skilledin the art without departing from the spirit of the invention or thescope of the appended claims.

Broadly the invention embraces providing a pontic the parts of which areinterchangeable and which is constructed so that the artificial toothcan be readily replaced. The pontic assembly comprises an artificialtooth secured to a metallic backing by means of a single pin. The pin isfused to the center of the tooth near its longitudinal axis andprotrudes from the posterior surface thereof at an angle to the centeraxis. This construction greatly strengthens the assembled pontic. Thepin is designed to fit within a tube which forms a part of the metallicbacking. This arrangement enables the tooth to be readily attached tothe bridgework and removed if necessary.

In the drawings:

Figure 1 is a side view in elevation of an 'artificial tooth and ametallic plate showing the pin and tube in broken lines.

Figure 2 is a posterior view in elevation of the structure shown inFigure 1.

Figure 3 is a view in longitudinal section of the tooth shown in Figure1.

Figure 4 is a view in longitudinal section of the metallic plate shownin' Figure 1.

Figure 5 is a front elevational view of the plate shown in Figure 1.

Figure 6 is a side view in elevation of a tooth and metallic plate,showing the pin and tube in dotted lines, the backing terminating shortof the biting edge of the tooth.

Referring more particularly to the drawings, there is illustrated inFigures 1 through 5, a pontic in which the metal plate extends to thebiting edge of the tooth. The arrangement shown in Figure 6 is identicalin structure with the exception that the metal plate does not extend tothe biting edge of the tooth.

In the drawings, numeral I designates an artificial tooth which is cutaway to provide a sloping shoulder 2 which overhan s a flat posteriorface surface 3. The tooth may be made of porcelain or any other suitableplastic.

The tooth is provided with a headed pin 4, the headof which is fused tothe tooth near its center axis to provide additional strength. Thispositioning eliminates the necessity of additional pins. The pin 4protrudes from the posterior surface 3 of the tooth at an angle to thecentral axis of the tooth.

The pin 4 is designed to secure the tooth to a metallic backing whichforms a part of the bridgework. This backing may consist of a metalplate 5 which is supplied to the practitioner with the tooth I. Thisplate 5 is in the form of an angle bracket designed to fit the shoulder2 and the posterior surface 3 of the tooth I. with an open tube 6 whichis fused to the upper surface of the arm 1 of the plate 5 andcommunicates with an opening in the remaining arm 8.

In attaching the tooth l to the bridgework, the plate 5 is fittedagainst the tooth l by inserting the pin 4 into the tube 6. Wax is thenflowed around the tube and plate to obtain an impression for thebacking. After the wax has hardened the plate is removed from the toothand a carbon pin is inserted into the tube 6. The impression is theninvested and the wax removed by heat in accordance with the usualpractice. The metallic backing may then be cast or soldered.

After casting, the carbon point is removed by passing a dental fissureburr through the tube and the casting is polished. In this manner aperfect alignment of the pin 4 and tube 8 can be obtained and the partsmay then be cemented together.

Preferably the plate 5 as well as the tooth I is supplied thepractitioner. However, the plate It is provided 3 may be omitted ifdesired. In this procedure the tube 6 is fitted over the pin 4 and thewax is flowed around the tube in taking the impression. The previouslymentioned lasting procedure is then followed. As a result, the tubeforms a part of the metallic casting.

In the event that the tooth should break, it can be more readily andaccurately replaced than in the constructions hitherto known. In theevent. of breakage, the head of the pin. 4' will be exposed and it isonly necessary to fasten a post puller to the pin and turn the leverscrew to remove the pin from the tube 6. When this operation has beencompleted, any remaining portions of the tooth will fall off and a newtooth of the same color and size as originally used may be cemented tothe metal in the manner pre viously described. Any excess cement willextrude from the open end of the tube 6 and can be removed.

While I have shown for purposes of illustration, the application. of theinvention to an incisor tooth, it is obvious that the same design can beused for the bicuspid and molar teeth. Moreover, it is understood.- thatvarious changes known to the art may be made in the procedure ofassembling the. pontic without departing from the spirit of the presentinvention.

I claim:

1. A dental pontic comprising an artificial tooth, a pin the. head ofwhich is fused to the center of the. tooth. on. the lower half of thelongitudinal axis thereof, a backing to fit a portion of the posterior.surface of the tooth and a tube open at both ends secured to saidbacking to form a rigid support therewith for. said tooth, said pinprotruding fromthe. posterior surface of the tooth at. an acute angle tothe upper half of the longitudinal. axis for. insertion into the opentube to whichit is cemented for securing the tooth to the backing.

2. A dental pontic comprising an artificial tooth, a pin the head ofwhich is fused to the center of the tooth on the lower half of thelongitudinal axis thereof, a metallic plate to fit a portion of theposterior surface of the tooth and a tube open at both ends fastened tosaid plate to form a rigid support therewith for said tooth, said pinprotruding from the posterior surface of the tooth at an acute angle tothe upper half of the longitudinal axis for insertion into the opentubeto which it isacementedifor.securing the tooth to the plate;

3. A dental pontic comprising an artificial tooth having a posteriorsurface cut to form a shoulder adjacent the root of the tooth, an anglebracket plate shaped to fit in the said recess against. the; saidposterior surfaces of the tooth, a pin the head of. which is fused tothe center of the tooth on thelower half of the longitudinal axisthereof, a tube open at both ends fastened to the outer surface of theportion of the plate which fits. against the shoulder portion of thetooth and forming a rigid. support; with said plate. for said, tooth,said tube communicating withan aperture. in. the remaining portion ofthe plate, and said pin. protruding from the. posterior surface of' thetooth. at an..acute angle to the upper half. of the longitudinal axisfor insertion into the open tube to which it. is cemented for securingthe tooth to the plate.

JOHN B. EAR/MAN.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

